Renewable Energy Applications

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Worcester Polytechnic Institute

Digital WPI

Major Qualifying Projects (All Years)

Major Qualifying Projects

April 2012

Renewable Energy Applications

Anthony Paul Ducimo

Worcester Polytechnic Institute

Kurt Ryan Snieckus

Nathaniel Louis VerLee

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Repository Citation

Ducimo, A. P., Snieckus, K. R., & VerLee, N. L. (2012). Renewable Energy Applications. Retrieved from

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Project JKM 5A11:

Renewable Energy Applications

A Major Qualifying Project Submitted to the Faculty

of

WORCESTER POLYTECHNIC INSTITUTE in partial fulfillment of the requirements for the

Degree of Bachelor of Science in Electrical and Computer Engineering

by ____________________ Anthony Ducimo ____________________ Kurt Snieckus ____________________ Nathaniel VerLee Date: April 13, 2012 Approved: _____________________

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Abstract

Sustainability is a widely discussed topic in engineering disciplines with the concept of renewable energy often serving as a focal point. The desire of many is to arrive at an optimal solution for the accumulation and distribution of renewable energy sources. When considering solar amongst the many resources for energy production there are many different hardware options that can be tested for their ability to transduce sunlight into electrical power or in their efficiency in converting electrical power for storage. A solar energy harvesting board was designed and built for efficiently collecting and storing energy in batteries, with an emphasis placed on measurement and testing capabilities. The final product allows for maximum power extraction from solar panels up to 250W, implementation of battery management algorithms, and may work in tandem with other units to charge battery banks. The system will serve as a foundation for hardware testing and future solar energy projects at WPI. By developing accurate measurement circuitry and power converter topologies, variances in solar panel and converter designs can be scrutinized while providing data about the system’s energy flow. Recorded data can be utilized to infer which hardware configuration offers the best solution and study system performance based on meteorological conditions.

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Executive Summary

The original focus of this project was to create a system to be featured in the lobby of Atwater Kent as a “21st_{Century Power Panel” to augment or supplement the old power panel originally installed in the}

lounge. After the existing power panel was moved to a new location, there was much consideration over what type of a system should be installed and what the project should focus on. Many different ideas were discussed, including wind and solar energy sources, systems for storing and displaying renewable energy data, a renewable energy site surveying device for determining the feasibility of a renewable energy system, repurposing and reusing currently available resources, and the installation of new renewable energy sources. Existing installations on the roof were surveyed and previous research and reports were considered for their findings. A cost and benefit analysis of each of the possible options was conducted. Ultimately, it was determined that the wind turbine was a poor resource and that the installation of solar panels and an appropriately designed power system for the panels was the best option.

After making the decision to construct a solar energy system, discussion of design of the system and then location for the panels began. Through Professor Looft, the ECE department head, contact was made with Jim Dunn, who runs a business called Future Solar LCC. The team discussed with Jim how different panels have different behaviors and characteristics such as their response to temperature, direct versus indirect sunlight, performance over age and so on. Jim offered ideas and donated six solar panels of three different models so the team could compare different kinds of technologies.

Atwater Kent was surveyed for the best roof site with a tool called a solar pathfinder that provides a shade analysis of buildings and trees conflicting with a particular site. The central area of the roof was picked as the best location. Two of the six panels are currently placed on the roof and ballasted with ballast pans that hold the panels down with paver stones. The pans are placed on top of non-slip mats to help prevent the pans from moving and from damaging the roofing material if they do shift. Additional ballast pans and solar panels are available to groups for future experimentation and research. Over the course of the winter and spring, the setup was surveyed occasionally and no obvious hazards arose. The core of the project was a system that would take energy from the solar panels and use it to charge batteries and drive DC loads such as lighting, radios, computer systems, and sensors. The basic solar energy harvester has a DC input from the solar panels and a DC output to a battery. Voltage and current are measured at both the input and the output, and a converter between the input and the output allows the voltage to be stepped down. Loads can be connected to the battery through a mechanism to protect from overcurrent and shut off the load if the battery is depleted. Because solar panels have a unique V-I characteristic, specific power electronics and control algorithms are needed to extract power from a solar panel at its maximum potential, known as the maximum power point. This power point is a dynamic point of the V-I curve that must be determined by making changes in the systems and then measuring how those changes affect the power extraction. The point can be affected by the amount of sunlight and the ambient temperature. In order to operate at the power point, voltage and current are measured on the input side of the system. Voltage and current measurement on the output side determines the state of charge of the batteries. The efficiency of the system can be determined using both the input and output measurements.

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System architecture, voltage measurement, current measurement, and converter topologies needed were discussed in detail. Precise current and voltage measurements were necessary to measure the efficiency of the converter effectively. The system was designed to handle in excess of 230W, 45V, and 9A to take input from all three different types of panels. A Hall Effect sensor was chosen to measure current, a differential amplifier was chosen to measure voltage, and a buck converter was chosen as the converter topology. A 16-bit ADC was used to digitize the measurements and an MSP430 was chosen to be the system’s microcontroller. After producing and testing a first revision of the populated printed circuit board with the aforementioned hardware, a second revision was created that included 12V, 5V, 3.3V, and -5V rails in order to power all parts of the system. The rails can derive power either from the system battery itself or from and external source. I2C and RS232 isolated communication ports were also added so that multiple harvesters could communicate with each other to work together and with a computer for collecting data and information.

The completed product is a highly integrated piece of hardware that can serve many purposes on both the experimental level as well as in real world applications. The board is engineered for precise measurements in order to allow its users to make better assessments of the efficiency of the system. It is designed to be connected to a computer and allow for collection of data over time to study trends and performance. The system can also function on its own in real world applications such as providing renewable energy lighting or power in developing nations, energy harvesting for solar vehicles, or power for instrumentation or radios in remote, inaccessible locations. This hardware ultimately represents a body of work that will enable future projects at WPI to continue to make strides in innovation and address and study issues in the solar renewable energy field.

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Figures

Figure 1: Solar Energy System Block Diagram ... 3

Figure 2: Wind Turbine Block Diagram ... 4

Figure 3: Hybrid Source Energy System Block Diagram ... 4

Figure 4: Universal Grid Tie Block Diagram ... 5

Figure 5: AK Energy Monitoring System Block Diagram ... 5

Figure 6: Energy Data Display System Block Diagram ... 6

Figure 7: Energy Usage Exhibit Design ... 7

Figure 8: Weather Assessment Module System Block Diagram ... 7

Figure 9: Solar System Monitoring and Display Block Diagram... 8

Figure 10: Wind Turbine Monitoring and Display System Block Diagram ... 11

Figure 11: Site Monitoring and Display System Block Diagram ... 13

Figure 12: Sanyo Green Energy Park Energy Monitoring Display ... 16

Figure 13: Solar Energy Harvester Block Diagram ... 17

Figure 14: System Block Diagram ... 18

Figure 15: System Control Decision Flow Diagram ... 19

Figure 16: Atwater Kent Building Roof w/ Installation Site Locations [19] ... 20

Figure 17: Monthly Insolation Ratings per Angle of Tilt ... 22

Figure 18: Solar Path Finder Example Shade Analysis Chart ... 22

Figure 19: Typical Solar Installation by Future Solar System LLC [22] ... 24

Figure 20: Solar Cell Circuit Equivalent [23] ... 25

Figure 21: Solar Panel V-I Curves [24] ... 26

Figure 22: Maximum Power Point Algorithm ... 28

Figure 23: Solar Energy Harvester Block Diagram ... 28

Figure 24: Buck Controller Block Diagram [25] ... 31

Figure 25: Voltage Measurement Circuit Design 1 ... 35

Figure 26: Ideal Electrical System w/ Embedded Measurement Circuitry ... 35

Figure 27: Actual Embedded Measurement Circuitry ... 36

Figure 28: Embedded Measurement Circuitry Using Isolation ... 36

Figure 29: Optocoupler Application Circuit [29] ... 37

Figure 30: Differential Amplifier Circuit ... 38

Figure 31: Embedded Measurement Circuity Using Difference Amplification ... 39

Figure 32: Voltage Measurement Error Analysis 1 ... 40

Figure 33: Voltage Measurement Error Analysis 2 ... 41

Figure 34: ACS712 Current Mapping Circuitry ... 42

Figure 35: Simplified Current Mapping Circuit ... 42

Figure 36: Solar Panel Curves Over One Day ... 48

Figure 37: Input Voltage Ripple ... 49

Figure 38: Output Voltage Ripple ... 49

Figure 39: Switching Node Waveform ... 50

Figure 40: Low Side MOSFET Drive ... 51

Figure 41: High Side MOSFET Drive ... 51

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Figure 43: Board 2 Input Voltage Calibration ... 53

Figure 44: Board 1 Output Voltage Calibration ... 54

Figure 45: Board 2 Output Voltage Calibration ... 55

Figure 46: Board 1 Input Current Calibration ... 56

Figure 47: Board 2 Input Current Calibration ... 57

Figure 48: Board 1 Output Current Calibration ... 58

Figure 49: Board 2 Output Current Calibration ... 59

Figure 50: Board 1 Input Power Contours ... 60

Figure 51: Board 2 Input Power Contours ... 61

Figure 52: Board 1 Output Power Contours ... 62

Figure 53: Board 2 Output Power Contours ... 63

Figure 54: Board 1 Efficiency Contours ... 64

Figure 55: Board 2 Efficiency Contours ... 65

Figure 56: Input Voltage Calibration ... 66

Figure 57: Output Voltage Calibration ... 67

Figure 58: Input Current Calibration ... 68

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Tables

Table 1: Solar Panel Cost Comparison ... 9

Table 2: Battery Cost Comparison ... 10

Table 3: Project Summaries ... 14

Table 4: Monthly Insolation Data ... 21

Table 5: Solar Panel Sunlight Exposure Percentages ... 23

Table 6: Converter Specifications ... 29

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1 Introduction

The primary objective was to develop a “21st_{Century Power Panel,” to supplant the 1800s era power}

panel on display in the Atwater Kent (AK) Laboratories lobby on the Worcester Polytechnic Institute (WPI) campus. The project as originally proposed to applicants was to develop a system to harness wind and/or solar energy and display information about the renewable energy generated. The system concept was to include an interactive control and include display of data about the power consumption both alongside the “power panel” and on the World Wide Web.

1.1 Report Overview

Initial research included reviewing available resources, previous MQPs and Interactive Qualifying Projects (IQPs) related to renewable energy harvesting. Ideas were developed into eight different project elements that posed an intellectual challenge and then combined to produce a system level design. Elements were grouped into three different possible MQP opportunities and the advantages and disadvantages of each were compared. After meeting with the project advisor, Professor John McNeill, and the Electrical and Computer Engineering (ECE) Department Head, Professor Fred Looft, a consensus on which project opportunity to pursue was reached.

1.2 Existing Resources

In 2008, a SWIFT Wind Energy System was donated and installed on Atwater Kent Laboratories by National Grid, a local electrical utility company. The intentions of the ECE Department faculty were that the turbine would foster more renewable energy research. Several projects have since been conducted related to its use.

1.3 Previous WPI Projects

Prior to this project, several MQPs and IQPs were conducted in the domain of renewable energy. These projects focused on monitoring potential locations for renewable energy harvesting, the instrumentation of renewable energy systems, and monitoring power consumption of various campus locations. Each of these previous projects set out to complete one or more of the tasks defined in this project. This project to be proposed intends to build on these outcomes of these previous projects.

Photovoltaization of WPI

This IQP studied various locations on the WPI campus and assessed the feasibility and potential output of a solar panel installation at each location [1]. This IQP was valuable for the development and installation of monitoring units that measure the wind and solar irradiance characteristics of potential locations.

Instrumentation of the Atwater Kent Wind Turbine

Upon completion of this MQP, a peripheral system to monitor and use the power output of the Swift Wind Energy System installed on the Atwater Kent roof was developed. The project disconnected the turbine from the grid-tie inverter and instead used the power output from turbine to charge batteries. The project also included voltage and current monitoring on the turbine output and made these measurements available on the ECE department webpage [2].

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Monitoring Electricity Consumption on the WPI Campus

The intention of this IQP was to characterize the current power consumption monitoring capabilities in place on the WPI campus. It also suggested new solutions to upgrade the current system. Because the power metering equipment on the WPI campus was incomplete, the report included energy consumption information of only certain buildings on campus. Group members also recommended the installation of a data collection system to monitor all campus buildings, citing several other campuses having installed such systems and reporting significant reduction in energy usage as a direct resultant [3].

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2 Project Conceptualization

Initially the definition of the MQP was flexible, that is, one of the major goals was to define project outcomes. With many areas of focus within the renewable energy umbrella, the three major categories were explored: system installation/integration, energy auditing, and renewable energy hardware. Additional subcategories were investigated, defined and discussed. It was then decided to combine these project elements into three pursuable MQPs.

2.1 Project Elements

When developing ideas for this project, they were viewed as building blocks of a renewable energy system. For this reason the ideas are presented as project elements, several of which would comprise a renewable energy system suitable for development by an MQP. Furthermore, these ideas were developed under the impression that collaboration would take place with another MQP team who would also be contributing project elements for an eventual system. The following details the eight final ideas developed.

2.1.1 Solar Energy System

The goals of this element were to install and instrument solar panels atop AK, with capabilities of driving a load and monitoring the energy production. A block diagram of this system can be seen in Figure 1.

FIGURE 1: SOLAR ENERGY SYSTEM BLOCK DIAGRAM

This project component would involve the purchase or donation of suitable solar panels, installation of the solar panels on the roof of Atwater Kent, the development of a maximum power point tracking (MPPT) converter to extract the maximum amount of power out of the solar panels and the measurement of the power consumption from the panels. The preliminary cost estimate of this system was based in the thousands of dollars. Existing resources for this project include lead acid batteries and a previous MQP involving the development of an MPPT system. Considerations for this project would involve obtaining funding, mounting the solar panels, evaluating the effectiveness of solar panels on the roof of AK, and the installation of wiring to power any loads within AK.

2.1.2 Wind Turbine Relocation

Because the wind turbine (as installed at the time of this report) was not generating an appreciable amount of energy, the goal of this project idea was to move the existing wind turbine to a location with an appreciable amount of wind. A block diagram of the system associated with the wind turbine is depicted in Figure 2.

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FIGURE 2: WIND TURBINE BLOCK DIAGRAM

This block diagram was adopted from the Instrumentation of the Atwater Kent Wind Turbine project [2]. This project idea proposed that the entire system be moved to another location after monitoring various locations for wind characteristics. A new monitoring system would also be implemented on the relocated turbine so that the amount of power generated could be displayed.

A rough cost estimate of this project was based in the thousands of dollars, aside from the cost of resources to move the turbine along with other project components required to create a system display interface. Some concerns with this project involved WPI policy regulations, building codes, and zoning laws governing the movement of the turbine to an ideal location. Other considerations would have to be made when deciding on an adequate period to monitor prospective locations and finally pooling resources needed to move the wind turbine.

2.1.3 Hybrid Source Energy System

The goal of this idea was to interface multiple renewable energy systems with one another to drive various AC and DC loads while meeting safety regulations. Figure 3 depicts the block diagram of this system.

FIGURE 3: HYBRID SOURCE ENERGY SYSTEM BLOCK DIAGRAM

This system would involve developing a unit to combine the power outputs of solar and wind renewable energy systems, and use the combined power to drive one or more AC or DC loads using a control system to allow the power from both sources to be used simultaneously.

The estimated cost of this project was based in the hundreds of dollars. Available resources included lead acid batteries to implement as an energy storage device, previous MQP designs of a battery charge controller, the wind turbine and inverter unit. Some considerations included the installation of wiring to drive intended loads and the design of a module for different sizes and types of renewable energy systems.

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2.1.4 Universal Grid Tie

Similar to the previous project idea, the goal of this project was to develop a system that could combine the outputs of multiple renewable energy sources and deliver that energy to the electrical distribution grid while meeting standard safety regulations for grid connections and grid connected equipment. A block diagram for this idea can be seen in Figure 4.

FIGURE 4: UNIVERSAL GRID TIE BLOCK DIAGRAM

This system would combine the power generated by solar and wind renewable energy systems, invert the DC to AC and deliver the power to the grid.

The cost of this idea was estimated to be in the hundreds of dollars. Previous MQP reports document example AC inverter designs that can be used in the development of such a system. It was also found that a design has been previously developed for a universal grid interface [4]. Considerations for this project involved the installation of electrical conduits if necessary and sizing the system for different renewable energy systems as well as regulations and codes associated with grid-tie systems.

2.1.5 AK Energy Monitoring

The system intended to monitor the energy consumed by the entire Atwater Kent building or individual distribution systems within AK and provide this information for display. A system block diagram of this idea is depicted in Figure 5.

FIGURE 5: AK ENERGY MONITORING SYSTEM BLOCK DIAGRAM

This idea involved developing a system to measure one or more power distribution points in AK. The devices would be designed to be electrically safe and non-invasive to allow for service of the distribution system when required. These measurements would then be stored and displayed by to the public by another system.

The cost of this idea was estimated to be within hundreds of dollars. Considerations for this project would involve working with WPI electricians regarding the installation of the monitoring devices and the necessary communications system to get the monitoring data to a display system.

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2.1.6 Energy Data Display

The endeavor constituted the development of a flexible system to display real-time data and information about potential and current renewable energy generation systems as well as energy consumption on the WPI campus. This display system would be located in the Atwater Kent Laboratories lobby as well as be available on the World Wide Web and would display the collected energy generation and consumption data to the public in an interactive and understandable manner. Figure 6 depicts the block diagram for this system.

FIGURE 6: ENERGY DATA DISPLAY SYSTEM BLOCK DIAGRAM

This system would monitor the energy outputs of the wind turbine and a prospective solar system along with the energy being delivered to loads within AK. The data collected would be sent to a database server and then displayed on both the ECE website and an LCD display in the building.

The cost range of this project was estimated to be within the range of hundreds of dollars. Existing resources included an LCD display, a department hosted website, a spare computer for data storage, and existing energy data resultant of previous MQPs. One thing to consider when executing this project would be the achievement of a critical mass of data.

2.1.7 Energy Usage Exhibit

The goal of this concept was to develop a museum style exhibit related to the energy production of a renewable energy system. A concept diagram of the exhibit design is shown in Figure 7. Upon user interaction, the exhibit would equate the energy produced by a renewable energy system over several different lapses in time.

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FIGURE 7: ENERGY USAGE EXHIBIT DESIGN

The cost of such an exhibit was estimated to be in the hundreds of dollars. Existing resources include the wind turbine energy data gathered as a resultant of a previous MQP [2]. Considerations would include seeking approval to install such an exhibit and the need for an appreciable amount of energy production to highlight the benefits of renewable energy harvesting.

2.1.8 Weather Assessment Modules

The goal of this project element was to develop devices to measure weather characteristics of prospective renewable energy sites. The data would be collected and used to estimate outputs of sized renewable energy systems if they were installed. The device would be self-sufficient, durable, and capable of communicating with a remote data server. Once developed the system would be installed in several locations on the WPI campus. A system block diagram is depicted in Figure 8.

FIGURE 8: WEATHER ASSESSMENT MODULE SYSTEM BLOCK DIAGRAM

This module would measure solar irradiance and wind speed amongst other weather characteristics. Solar panels would also be used to provide power to the system making it self-sufficient. The module would transmit the data recorded to a remote server for display. The display aspect was intended to educate the public about what renewable energy opportunities could be explored on the WPI campus.

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The cost of this idea was estimated in the range of hundreds of dollars per unit. Existing resources included a weather measurement station which could be used a foundation for prototyping. Considerations for this project include developing a reliable system for communication between units and the data display system, the permissions required to install these devices on campus buildings, the determination of appropriate site locations, and the time required to make multiple units.

2.2 Project Ideas Discussion

After developing a platform to evaluate each idea they were presented to Professor John McNeill, the project advisor, and the MQP team potentially collaborating with this project to discuss and evaluate all of the available ideas. It was found that the other MQP would most likely be developing a display system separate from a renewable energy system in the AK lobby. Realizing that the other MQP could use data from the proposed project, or possibly serve as a load for the project, it was decided to concentrate on combining aspects of the aforementioned ideas into three possible projects independent of the other MQP team’s work.

2.3 Project Possibilities

The following sections set out to describe the three projects, as compilations of one or more of the project ideas previously discussed. Each one of these projects was evaluated with respect to cost, pros, cons, and best and worst case scenarios.

2.3.1 Solar Monitoring and Display

Proposal

The purpose of this project would be to install solar panels on the roof of AK, have it drive a load, and monitor its output characteristics. The measurements would be compared to data collected regarding to the power usage by the entire AK building. The comparison of power generated versus power distributed would be displayed for the public to see. Weather information gathered at the site of the solar arrays would also be acquired in an attempt to correlate weather characteristics with the arrays power output. Figure 9 depicts the block diagram of the Solar Monitoring and Display system.

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Anticipated Outcomes

Ideally, this project would entail the installation of a solar panel array that would power display system under construction by the other MQP group. The solar system would implement maximum power point tracking to extract the power from the solar array efficiently. Monitoring equipment would be designed to measure the energy characteristics of the solar system and the AK distribution point. Another monitoring unit would either be designed to monitor the weather conditions of the solar array site. The other MQP team’s display unit could have been used as the display medium for the collected data, it would be developed to interface with the monitoring systems and descriptively quantify the power consumed and produced in terms that any member of the public could understand. The data would also be made available on the ECE website. The display would allow for real time presentation of data along with data trends over an elapsed time. Weather characteristic trends would also be displayed alongside of the power outputted by the solar system allowing the public to infer correlations between the data sets.

Cost

The main component cost of this endeavor would involve the installation of a solar system. An installation quote was estimated at $14,300 for a minimum size of a 2000W system (see appendix for solar calculator input parameters) [5]. Another option was an 850W system with other accessories that needed additional mounting hardware to mount the panels to the roof the system alone was $4,560

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. The individual panels of the system (along with some undesired accessories) could be purchased at $480 per 85-watt panel [6]. Individual solar panels were found to be cheaper if bought online. Table 1 summarizes the costs of solar panels that could be purchased through online distributors [7,8,9,10]

TABLE 1: SOLAR PANEL COST COMPARISON

Sharp solar panels offer the best deal with considerations to cost and system size. In purchasing the panels alone, additional mounting hardware would be required to install the panels. It was advised that the installation require no direct anchoring to the roof of the AK. Therefore, a ballasting system, which mounts the panels to a rack and the racking unit itself is weighed down was chosen to be an alternative type of installation. A conservative estimate of the racking system was priced around $200 [11].

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Another component of this system would pertain to power storage. It would be desired that the system charge batteries, which would drive a load when there is little or no sunlight. Table 2 lists the cost of power storage depending battery type and power capacity specifications [12,13].

TABLE 2: BATTERY COST COMPARISON

In this competitive analysis, the UPG model offers a larger capacity at less of a cost. After compiling all of this preliminary cost information, a conservative overall cost for this endeavor was calculated at $4000 allotting additional funding to fulfill the remainder of the project’s objectives

Pros

Implementing such a system would provide a concrete demonstration of harnessing and utilizing renewable energy. If it were able to power the LED wall, it would show how a green energy system could efficiently drive DC loads in an uncomplicated manner. The system would also allow correlations to be drawn between weather characteristics and the energy harnessed by a renewable energy system via user interaction with the display unit.

Cons

Once installed, the solar array would need eventual servicing. Insufficient designs in the display and the monitoring system would also increase the need for system service. This could have posed future maintenance costs for the system after its implementation. The display may have required some facilitation to encourage interactive use. The solar system would provide an unregulated power output because its dependency on sunlight so loads would have to be driven intermittently.

Challenges

Possible areas of concern involved insufficient funding for the installation of solar panels that would bring the project to an immediate halt. Upon inspecting the roof of Atwater Kent, there existed only a limited space to mount a solar panel array. In order to power the LED wall, conduits would have to be installed to route the electrical conductors needed. The installation costs of conduits from the roof to the lounge could inhibit powering the LED wall. If insufficient power were generated by the solar array, displaying the data regarding the system’s output would be frivolous. Difficulties could arise when attempting to develop a monitoring system that also properly interfaces with the display aspect of the project. Constant monitoring of AK’s power distribution may stir up some issues of legality and practicality to the point that it may not be possible to monitor it continuously. In addition, the time it takes to perform one or more of the desired tasks may leave little or no time to complete the rest of the tasks in the duration of one MQP.

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2.3.2 Wind Turbine Monitoring and Display

Proposal

The purpose of this project was to survey prospective locations for a wind energy system, move the turbine atop of AK to a better location, and monitor its output. The output characteristics would be compared to the power delivered by a distribution point in AK. The comparison of power generated versus power consumed would be made visual via a display module. Weather characteristics of the site of the turbine would be collected and displayed to draw correlations between the weather and the power output of the turbine. The block diagram of this system is depicted in Figure 10.

FIGURE 10: WIND TURBINE MONITORING AND DISPLAY SYSTEM BLOCK DIAGRAM

The execution of this would assess prospective sites for the harvesting of wind energy. This could be used for future renewable wind-energy system installations about campus. Another desired goal of this project would revolve around the movement of the wind turbine to a location with an appreciable amount of wind. The wind turbine would be configured to either drive a load or interface with the electrical grid. A monitoring system would be implemented to communicate remotely with a server allowing for the display of real time information regarding the power output of the system and its ambient weather conditions. An AK power distribution point would be measured and the data collected would be used to compare energy consumed within AK to the energy produced by the wind turbine. The energy would be quantified into units that the public would find relatable. Ideally, the data collected would be displayed utilizing the interactive display system under development by another MQP group; it would also be made available on the ECE website.

Cost

It proved to be difficult to estimate the cost of moving the wind turbine. Most of the services listed online dealt primarily with large, commercial scale wind turbine installations, not with smaller residential installations. After consulting Professor James O’Rourke and Professor Alexander Emanuel, it was found that the cost of the original installation was around $10,000 [14]. It was also advised the cost of the installation did not accurately reflect the cost of such a procedure. It was revealed that the installation of the wind turbine was executed with a coordinated effort of members of the WPI facilities department, members of the ECE department, and members of the National Grid workforce not by a

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professional installer. It was relayed that the cost of a professional installation could be twice that of the above amount [15]. Being conservative, the cost of the project was estimated at $20,000+.

Pros

Implementation of this system would demonstrate real use of alternative energy via the display its power output. Moving the wind turbine repurposes an underutilized resource, as the turbine, upon playful observation, was not in a prime location. If moved to a more visible location on the campus the wind turbine could serve as an icon to WPI’s initiative to move towards a greener future. The use of a wind turbine allows for a more frequent and regulated harnessing of power since it can operate at all hours of the day. One of the existing resources available is a grid tie supplied with the turbine therefore interfacing it with the electrical grid is a plausible goal.

Cons

Other aspects of this project may have undesired corollaries associated with it. Since the wind turbine may be grid connected, there will be no way to present a visible load driven by a green energy system to the public. Reinstalling the wind turbine involves construction, management, and their associated costs. Moving the wind turbine removes a renewable energy icon from the Atwater Kent Building. If the system were to be implemented it would need some intermittent service to keep the system running. Again, the display apparatus may require some facilitation to encourage system interaction.

Challenges

Issues that may arise when pursuing this idea include an insufficient period to monitor prospective sites. Limited observation time could result in insufficient data generation possibly imposing a wrongful decision being made concerning the movement of the turbine. Another possible scenario is that resources may not exist to move the wind turbine. One undesirable facet of this project is that the power generated by the wind turbine may be too insufficient to display in real time or over short windows of time. There is also a possibility that the monitoring system, once in place, has issues communicating with the display module. Alternatively, the monitoring unit developed may not be adequate for use or interface with the display unit. Interfacing this system with the peripheral display system might be out of the question depending upon the other MQP groups design.

2.3.3 Site Monitoring and Display

Proposal

This MQP would involve developing multiple weather monitoring units and installing them at prospective locations for renewable energy harvesting across campus. The data collected would be used to approximate power outputs of sized renewable energy systems located at each site. These calculations would then be compared with the power delivered by a distribution point within AK. The energy characteristics would then be displayed for public viewing. Figure 11 shows a block diagram of the system.

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FIGURE 11: SITE MONITORING AND DISPLAY SYSTEM BLOCK DIAGRAM

Ideally, the project would involve the development of multiple durable, self-powered, monitoring units designed to have no moving parts and measure weather characteristics such as wind speed, solar irradiance, barometric pressure, etc. A separate monitoring unit would be developed to measure a power distribution to AK from the grid. Each of these units would be capable of transmitting data to a central server for further use. The data would be used to compare possible power production of a sized renewable energy system with current power consumption of a facet of AK both in real time and over specific time intervals. The quantification of energy would be displayed in a qualitative manner, easily understood by the public. The display medium desired would be the interactive display previously mentioned.

Cost

An estimate was put together to price out a per-unit cost for each weather monitoring module. It was reasoned that the weather instrumentation would cost around $100. The printed circuit board (PCB), assorted circuit components, and weatherproof enclosures were priced at $180. A wireless communication module would cost about $40. The irradiance measuring solar panel would run a cost near $90. Lead acid batteries used as a power storage unit for each module would cost approximately $25. The mounting hardware, which would vary depending upon installation location, was estimated to cost $40. Accounting for the possibility of additional needed componentry the per-module cost of this endeavor ranged between $400 and $600 [16].

Pros

The development of this system raises awareness in the public as to renewable energy potentials that could but have not been implemented at the current time. This system would create some political pressure to generate funding for the installation of various renewable energy systems. Self-sufficient monitoring modules would emanate the use of renewable energy by harvesting it to power system components. The system as conceptualized by the group would be wireless and require no complexities involving installation of these units.

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Cons

Developing multiple monitoring units utilizes a considerable amount of resources with one of those resources being time. The system may need to be routinely serviced especially in severe weather conditions. The fact that there may be many locations to manage and certain locations may have issues with ease of facility access. This would create additional costs for the ECE department to handle. It is possible that these units could backfire in the desired green energy initiative. If the modules were inaccurate, calculations would not reflect the actual amount of energy that could be harvested. On the other hand, it could be that the prospective sites are not as ideal as once perceived. The system may possess a yearly downtime due to winter weather conditions. In addition, the display module may require some facilitation to encourage public interaction with the exhibit.

Challenges

While pursuing this project several issues may arise, one of them being the denial of approval to install these monitoring units across campus. An inability to transmit the data would bring most of the project to a halt. If the monitoring devices are not self-sufficient, it may detract from the nature of the system to promote harvesting renewable energy. Restrictions regarding the locations possible install locations may limit the number of monitoring modules being put into place. Display interface issues may arise when trying to communicate with the modules. The weather data (mainly irradiance or wind speed) when manipulated to estimate power delivered a sized renewable energy system may theoretically produce insufficient amounts of power, making display purposes frivolous.

2.4 Project Discussion and Decision

Once the final three MQP project ideas were defined, explored, and estimated for cost, they were presented to Professor Looft, the ECE department head. Once presented, a brief discussion about the feasibility of each project took place. Each idea was carefully considered by the team to determine which project would be the best choice. Factors considered were economic and technical feasibility, impact of the overall outcome, challenges presented by the projects, available resources, and possible pitfalls. Table 3 summarizes the findings of the discussion.

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Judging each of these project’s pros and cons against MQP priorities and other factors it was deemed that the wind turbine project was too costly when weighing the necessary finances, resources, and labor to execute the project. One of the major concerns was the feasibility to complete such a project in one academic year, considering it would take a substantial amount of time for WPI’s upper management to approve such an endeavor. The site-monitoring project was ultimately discarded because it would take a considerable amount of time to locate and seek approval to install theses apparatuses about the campus. The project would also not provide a concrete example of renewable energy usage as it would only report the green energy potential of the site. Beyond that, this project would strain the resources of the ECE department when system maintenance was required. It was finally decided to pursue the solar system project as it met the demands of a Major Qualifying Project while satisfying the majority of the decision factors. Modifications made to the scope of the solar project are discussed in the following chapter.

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3 Proposed System Design

Once the solar energy harvesting and information display project was chosen, the system could be designed and implemented. The subsequent sections briefly discuss systems in existence similar to the prospective project and details functionality of the system to be developed along with the work necessary to complete the project.

3.1 Related Systems

Currently there are technologies and practices in place that furnish and install solar systems and auxiliary equipment that measures the electrical characteristics of the system. This subsection of this report discusses a couple of practices already in existence.

Solectria Renewables

One company, Solectria Renewables LLC, develops products specifically dealing with solar systems. It also offers various types of system monitoring. Solectria designs and manufactures inverters, which convert the DC output of a solar array to AC power to interface with the electrical grid. In addition, they also manufacture string combiners that combine arrays of solar panels for various system configurations. Solectria offers monitoring packages that include informational displays local to system equipment or various subsystems and on-site data display kiosks. Information is viewable online utilizing web based monitoring. Data is periodically updated and stored and trends can be observed over given time intervals [17]. A more detailed monitoring system is realized and reviewed in the next subsection.

Sanyo Kasai Green Energy Park

In Japan, Sanyo has constructed a green energy park, a corporate facility harvesting solar energy on a massive scale utilizing the technologies that are designed and developed within the complex. The park employs an energy monitoring system that measures the energy consumption, the production of renewable energy from the solar system installed, and equates the renewable energy produced to the reduction of carbon emissions [18]. The monitoring display kiosk is shown in Figure 12.

FIGURE 12: SANYO GREEN ENERGY PARK ENERGY MONITORING DISPLAY

Our project plans to be a hybrid of the aforementioned systems, displaying the solar system’s electrical characteristics from both a system level of abstraction and a subsystem level. It will report on not only the overall system outputs but will reveal data on the equipment used to comprise the system. The data

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will have a detailed and understandable display medium to educate all those who enter the Atwater Kent Building and visitors to the ECE department’s website. The information will also be used to extract information critical to the devices involved with the conversion and storage of solar energy.

3.2 Functional System Description

The final proposed system involved the installation of six solar panels atop the roof of the Atwater Kent building; the precise location was determined by a solar path analysis discussed in a later section of this report. Each panel had conductors leading from the panel, and terminated at an overcurrent protection device located in room AK317. The six solar panels consisted of two identical solar panels each from one of three manufacturers. In this way, each panel was compared to another identical solar panels as well as panels from other manufacturers.

Separate maximum power point, DC-DC converters were developed to convert the power outputted by each panel and either charge batteries or drive a DC load. The converter would find the maximum power point using a perturb and observe algorithm.

The converter would continually take measurements of the power it outputted, comparing one measurement with a previous measurement and adjust the duty cycle of the switching circuit performing the conversion to output optimal power. The maximum power point converter was embedded within a power management subsystem designed for a single solar panel. Figure 13 depicts the block diagram of the panel management circuitry.

FIGURE 13: SOLAR ENERGY HARVESTER BLOCK DIAGRAM

The Solar Energy Harvester actually consists of three separate blocks working as one. The DC-DC converter is controlled by a local microcontroller that runs the maximum power point algorithm based on measurements taken from the measurement blocks and adjusts the converter circuitry accordingly. Measurement apparatuses would be designed and built to measure the output of the panel and the output of the converter. Specifically, the measurement devices would measure the voltage and current values at each point in the system. The local microcontroller would poll an analog to digital converter for the voltage and current values measured, adjust the converter operation, and send the data to a system “master” microcontroller where it will be processed. This local “slave” microcontroller could

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also receive information from the master microcontroller and adjust the converter operation accordingly. A system block diagram is depicted in Figure 14.

FIGURE 14: SYSTEM BLOCK DIAGRAM

The slave microcontroller of each panel management circuit sends data to a master microcontroller, which in turn transmits the data to a PC. The stored data would then be processed and displayed online and on an LCD monitor in the lounge area of the Atwater Kent building. From these measurements, additional electrical characteristics such as power are calculated and displayed. By measuring the converter input and output, the efficiency of the converter can be calculated. The conditions of the batteries designed to store the converted solar energy are also monitored by voltage measuring circuits. The master microcontroller receives data relevant to the battery and either continues charging the battery or diverts power to DC loads. The master microcontroller would also send information to the panel manager blocks and alter converter operation. The control decisions made by the master microcontroller are summarized in a flow chart in Figure 15.

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FIGURE 15: SYSTEM CONTROL DECISION FLOW DIAGRAM

As a safety feature, the master microcontroller had the ability to cease system operation if any hazardous conditions were detected. Using the battery-monitoring feature, the master microcontroller would decide what source would be used to drive the DC loads. If the batteries possessed enough charge, the system would drive the loads from the battery banks, if the charge in the battery bank was depleted, the electrical grid would drive the loads whilst the solar panels would charge the batteries. If the batteries were fully charged, and sufficient power was still being output by the panels, the system would divert power directly to the DC loads.

Another optional avenue was to include a user-controlled aspect to the project. Using a display medium such as an LCD touch panel a user would be able to interactively turn on and turn off DC loads. The system would incorporate its own automatic override if user interaction would jeopardize the integrity of the system. Ultimately, the progress made in the development of other subsystems would decide whether to pursue this option.

4 Detailed Design

This section of the report will address the decisions made in the design process of the project in three separate categories: solar panel installation, circuit design, and system integration and interface. The research and experimentation to arrive at such decisions will also be covered.

4.1 Solar Panel Installation

This subsection of the report discusses the research, consultation, experimentation, and execution of solar panel installation.

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4.1.1 Site Location

Many factors were taken into consideration when deciding where to install the solar panels. The length of cable that would need to be run, the visibility of the panels, the amount of solar energy a given area is exposed to, the susceptibility to damage that the panels were exposed to along with how the installation may damage the surrounding area and the roofing materials were the top concerns of the group. Initial research was conducted to calculate the potential amount of solar irradiation collected by the panels under various conditions. Next, three sites were chosen based on the natural and artificial surroundings of the site and the public visibility of the panels. The site locations are marked in the Figure 16.

FIGURE 16: ATWATER KENT BUILDING ROOF W/ INSTALLATION SITE LOCATIONS [19]

Site 1 was chosen to address the possibility of mounting the solar panels such that they would hang over the lip of the roof of the building. Making the panels visible to the public by mounting them in such a will reflect WPI’s initiative for a greener future. Site 2 minimizes the shading created by surrounding structures. Site 3 would minimize the amount of shading the panels would be exposed to and decrease the conductor length needed to connect the panels to a load. As mentioned before the cabling would enter the building via an opening beneath the base of the wind turbine.

After determining the sites, the path the sun would take over an hourly and monthly basis was analyzed serving as one of the deciding factors in which site was finally chosen.

Insolation Data

Insolation is a measurement of the amount of solar energy a specific area receives per day. It is based on many different factors, most importantly the latitude line that the area of interest is on. The

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instantaneous solar radiation is expressed in , while solar radiation for a single day can be measured in

or the amount of work produced by a square meter solar panel of ideal efficiency each day.

Reliable insolation data is available from the NASA Atmospheric Science Data Center [20]. This data provides information about the amount of sunlight energy delivered relative to a specific latitude and longitude for a specific month. Several different measurements are made based on tilts relative to horizontal and relative to the equator. Table 4 is a series of measurements for each month averaged over a 22-year period based on different types of angles and measurements at a latitude specific to Worcester, Massachusetts.

Position Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Total Direct 3.31 4.07 4.33 4.29 4.50 4.65 5.18 4.87 4.64 4.05 3.14 2.95 4.17 0° 1.80 2.62 3.61 4.46 5.13 5.49 5.61 4.99 4.04 2.93 1.89 1.54 3.68 27° 2.82 3.59 4.32 4.73 5.09 5.23 5.48 5.15 4.64 3.84 2.80 2.50 4.19 42° 3.19 3.88 4.42 4.57 4.73 4.78 5.04 4.89 4.65 4.08 3.10 2.86 4.18 57° 3.37 3.95 4.29 4.20 4.17 4.14 4.38 4.41 4.42 4.09 3.23 3.06 3.97 90° 3.09 3.35 3.26 2.80 2.54 2.45 2.57 2.79 3.19 3.37 2.89 2.86 2.93 Optimum Angle 3.39 3.95 4.42 4.74 5.21 5.51 5.66 5.19 4.68 4.11 3.24 3.09 4.43

TABLE 4: MONTHLY INSOLATION DATA

Insolation measured in is tabulated by month based on a panel pointed normal to the equator tilted at a specified angle. A direct measurement of insolation with a panel pointed normal to the sun (tracking the movement of the sun) is given as well as the optimum angle, the ideal tilt angle of a panel specific to the month. For the scope of this project, tracking the sun with the panel normal to the sun is not feasible. Instead, an ideal fixed angle will need to be chosen with consideration to the data available, the mounting method used, and the site chosen.

While it may seem logical to choose the angle that produces the highest annual insolation numbers, when considering a graph of each different angle over the months (see Figure 17) more about the availability of energy is revealed. While certain angles will produce higher annual values, others will produce energy at a steadier rate through the seasons. The angle the panels are currently mounted at is fixed because of the nature of the panel mounting system currently used that was donated to the project. Future mounting systems may make it possible to experiment with different angles.

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FIGURE 17: MONTHLY INSOLATION RATINGS PER ANGLE OF TILT

Solar Path Finder Measurements and Results

With the three sites chosen, data was collected about the path the sun would take on a daily basis over different seasons of the year. A device known as a solar pathfinder was used to map out how the surroundings of the site would cast shadows over a daily basis throughout the year. The solar pathfinder apparatus (see Figure A-1) was oriented to compensate for the tilt of the earth’s axis, the latitude and longitude of the site, and the fact that the true north is off from the magnetic north measured by a compass (magnetic declination). A dome would be placed over a shade analysis grid and any object that would cast shade over the location would be reflected in the dome. The outlines of these reflections were traced and used to interpret percentages of the sunlight seen by a solar panel installed at this location. An example of a filled shade analysis grid is depicted in Figure 18.

FIGURE 18: SOLAR PATH FINDER EXAMPLE SHADE ANALYSIS CHART

0 1 2 3 4 5 6

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

In

so

lati

o

n

Insolation By Month, Angle

DIR 27 42 57 OPT

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The outline of the reflected objects covers up portions of the chart beginning at the perimeter of the chart itself. The grid on the chart marks percentages of the total daily sunlight spread out over each half-hour of the day from the approximate sunrise to the approximate sunset (5am to 7pm). Adding up the percentages on a particular horizontal curve (month) not covered up by the reflection trace provides the total daily percentage of sunlight exposure. The varying amount of daylight in each month is compensated by the curvature of the horizontal axes and the change in the half-hourly percentages along these axes [21]. Each of the sites was analyzed twice and the monthly percentages of sunlight exposure were computed. For a better view of the shade analysis charts see Figure A-2 through Figure A-7 in the appendix. The results are listed in Table 5.

TABLE 5: SOLAR PANEL SUNLIGHT EXPOSURE PERCENTAGES

The data reflected that the optimal location for installing the solar panels would be Site 3. Site 3 also offered the benefit of a shorter conductor run from panel to the eventual load. In addition, the installation of panels at Site 1 would have required additional hardware to make the panels directly visible to the public; it would have also introduced additional liability concerns. Because of the mounting system used, Site 2 served as the best compromise between conductor length and shading percentage.

4.1.2 Initial Installation

The solar panel mounting procedure involved bolting down the solar panels to a metal structure known as a pan. These pans are bolted together one behind another to form multiple columns of solar panels. These columns are placed adjacent to each other to maximize the roof space. The mounting hardware is secured to the roof by weighing down each pan with a series of paver stones. This procedure is illustrated in Figure 19.

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FIGURE 19: TYPICAL SOLAR INSTALLATION BY FUTURE SOLAR SYSTEM LLC [22]

This installation procedure provides a non-invasive alternative to typical solar panel installations. To prevent damage to the roofing material, anti-slip matting is placed between the metal installation hardware and the roofing material.

The solar panels installed were donated by a Jim Dunn, a WPI alum and President of Future Solar Systems LLC. The six solar panels consisted of two 215W Sun Power Panels (SPR-215-BLK-U), two 230W Sun Power Panels (SPR-230-WHT-U), and two 230W Canadian Solar Panels (CS6P-230P). One of each type of Sun Power Panels was mounted on the roof initially and eventually, through coordination with WPI’s facilities staff and the ECE department staff, the remainder of the solar panels would eventually be installed.

4.2 Solar Panel and Energy Harvesting Theory

Before getting into the details of the system operation, it was important to understand the panel from a circuit modeling perspective. In doing this, the specifications and end goals of the energy harvesting system could be defined.

4.2.1 Solar Panel Theory

Solar panels are comprised of strings of individual solar cells, a semiconductor device typically fabricated out of silicon. A solar cell is modeled as a constant current source up to a specific voltage, at which point the current falls off exponentially. This cell voltage is typically around 0.6V-0.7V for a silicon cell, but varies based on the cell’s chemical composition and manufacturing processes. The voltage of a cell is inversely proportional to temperature governed by the thermal voltage of the semiconductor material. The current produced by a solar cell is directly proportional to the intensity of light at the wavelengths the cell responds too, and directly scales based on the size of the cell, so a cell with twice the area will produce twice the current. Figure 20 shows the circuit equivalent of a single solar cell.

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FIGURE 20: SOLAR CELL CIRCUIT EQUIVALENT [23]

The current source, a direct function of sunlight, has some series and parallel resistance, RS and RSH

respectively. These resistances are due to the natural resistive properties of the silicon. The output current and voltage of the cell are defined by the equations:

where VCELL is the voltage across the model’s current source. These equations are linked by the V-I

characteristic of the diode (Shockley’s diode equation):

The temperature dependence of the panel is reflected in the equation - the thermal voltage of the diode contributes to the variations in the output voltage based on ambient temperature. The ability of a solar cell to produce power is measurably decreased in the summer and increased in the winter. Taken directly from the datasheet of one of the solar panels, Figure 21 reflects the general shape of the voltage and current relationships for this circuit model.

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FIGURE 21: SOLAR PANEL V-I CURVES [24]

The falling exponential shape of the graph is largely defined by the exponential characteristic of the diode in the circuit model. The series and shunt resistance also give a slope to the approximately constant current and constant voltage sections of the graph. As power is the product of voltage or current, there is a point on the curve where the maximum power of the cell can be extracted.

Solar panels, as previously mentioned, are composed of many solar cells connected together. Cells can be connected in series, parallel, or combinations thereof, but large panels in excess of 100W are nearly always connected in one series string because of the I2_{R losses associated with parallel connections.}

Series connected cells produce V-I characteristics with the same output current as a single cell at a much higher cell voltage. The only drawback is that a single cell being blocked from light will appear as a resistance to all other cells in the panel. Various strategies can be used to mitigate these effects, such as bypass diodes every few cells.

In order to maximize the effectiveness of a solar panel, energy should be extracted at the maximum power point, where the effective impedance of a load connected to the panel must be directly matched to absorb power at the current and voltage corresponding to the maximum power that the panel can produce. Because the current varies with illumination and the voltage varies with temperature, this point can change dramatically based on the current conditions and must be “tracked” by a load that can change its apparent impedance. While loads with relatively constant impedance such as a battery or LED can be connected directly to a solar panel, it is in the interest of efficiency that a more intelligent energy conversion system is implemented to use the panel effectively. This is accomplished with a circuit such as a DC-DC or DC-AC converter capable of changing the Input-Output transfer characteristic alongside a measurement and control system capable of finding the most efficient power point. This technique is known as “maximum power point tracking”.

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Because the location and magnitude of the maximum power point varies widely based on environmental conditions and the type and characteristics of a solar panel, it is necessary to “track” this point. Essentially any given point on the V-I curve of a solar panel under specific conditions has an associated load resistance which, when attached, will power from the panel at that specific point. Note that there are multiple pairs of points that have the same associate power, but different associated load resistances. In order to draw power from a panel at the maximum power point, a system must be able to find that point by either having previous knowledge of the panels characteristics or by “experimenting” with different loads until the one that extracts the most power is found.

Most loads attached to a solar system will be nonlinear in nature, such as batteries that are a relatively constant voltage with a small series resistance. For this project, a buck converter was chosen (discussed later in 4.3.1), which exhibits the input output voltage relationship:

This relatively simple relationship links the expressions for the solar panel and the battery. Essentially, the converter exchanges voltage for current and current for voltage at some efficiency, which allows us to “pick” points on the solar panels V-I curve by changing the apparent resistance of the battery. This is controlled by changing the duty cycle, D of the converter.

By making measurements of the power flowing into the converter, we can keep track of which duty cycle produces the most power and operates at that point until the maximum power point moves elsewhere, at which point the duty cycle is changed again until optimum conditions are found. This technique, and flow diagram of which can be seen in Figure 22, is known as a simple “Perturb and Observe” algorithm for finding the maximum power point. While there are many different ways to implement this algorithm, all of them involve either making changes and observing or having records or knowledge of the panel characteristics.

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FIGURE 22: MAXIMUM POWER POINT ALGORITHM

4.3 Circuit Design

The measurement and converter module was the focus of this project. This module involved the design of a DC-DC converter, accurate voltage and current measurement and digitization, and a digital control system with feedback. The result of this design is a circuit that converts DC power from the solar panel to a level usable by standard DC loads such as a battery or lighting system. Additionally, the module is designed to output the current and voltage measurements at both the both input and output of the converter in a manner accurate enough to determine the efficiency of the entire module. A block diagram that details the connection of each of the major parts of the module can be seen in Figure 23.

Renewable Energy Applications

Worcester Polytechnic Institute

Digital WPI

Major Qualifying Projects (All Years)

Major Qualifying Projects

April 2012

Renewable Energy Applications

Anthony Paul Ducimo

Kurt Ryan Snieckus

Nathaniel Louis VerLee

Follow this and additional works at:

https://digitalcommons.wpi.edu/mqp-all

Repository Citation

Project JKM 5A11:

Renewable Energy Applications

Abstract

Executive Summary

Contents

Figures

Tables

1 Introduction

1.1 Report Overview

1.2 Existing Resources

1.3 Previous WPI Projects

2 Project Conceptualization

2.1 Project Elements

2.2 Project Ideas Discussion

2.3 Project Possibilities

[6]

2.4 Project Discussion and Decision

3 Proposed System Design

3.1 Related Systems

3.2 Functional System Description

4 Detailed Design

4.1 Solar Panel Installation

Insolation By Month, Angle

4.2 Solar Panel and Energy Harvesting Theory

4.3 Circuit Design